In the motion picture industry an original motion picture negative film is exposed during a camera exposure operation, developed into a processed camera negative and subsequently operated upon in one of several ways to produce an imagery product. In prior art analog systems, film dailies or rushes were conventionally produced as a motion picture was shot. These dailies or rushes were processed and then viewed by the director, the producer, the film editor, etc. working on the production to determine whether the scenes shot were acceptable. Each person on the production team assessed the dailies for different elements relevant to their respective roles in the team. That is, dailies or rushes were printed on film. The cinematographers and directors could see the results of the previous day's work in a format that faithfully “previewed” what the final release would look like. A language developed between cinematographers and the “timer” at a lab where a director of photography (dp) could either literally dictate the color exposure intervals (e.g., lites), and hence the look of the dailies. Alternatively, assuming a relationship of trust which existed between the dp and the timer, the timer would choose the lites based on discussions with the dp, and the dp could verify, based on these lites, that the exposure was correct and that enough latitude was present on the negative for future color correction during the answer print process.
More specifically, with the dailies, “Printer Lite” information was provided which assisted the cinematographer/director of photography to determine whether the scenes were shot with a satisfactory exposure. This Printer Light information was determined from the settings of a conventional motion picture film printer required to produce a print with densities aimed at a specific laboratory. This information was obtained by passing white light from a scene through dichroic filters to split the light into its three components, red, green and blue, The three light components were used to expose a test film strip from which the densities corresponding to the intensities of the red, green and blue components of the light could be measured and compared with standard densities which correspond to an “ideal” exposure. The densities produced by the red, green and blue light components on the test film strip gave an indication of the exposure given to the original film as the scene was recorded. The “Printer Light” information provided repeatable and reproducible values from which a cinematographer/director of photography could order the color correction of the film in a manner understood by a color correction specialist (colorist) or “timer”.
Today, however, there is an increasing demand for motion picture negative film to be transferred to video, and the film is never printed as such, as most film programs made specifically for television, for example, episodic shows, movies of the week and commercials, are transferred to video tape prior to showing. Telecine machines enable this transfer to be achieved. That is, color negative film information (from a camera negative) or the color print film information (from an interpositive) is transferred into a video signal using a telecine transfer device in a telecine scanning process. As with the optical process, the interpositive is a negative copying material that is used to produce a positive copy with the same contrast as the original negative and the same extended range of the scene. This element is then used in the trade as the element to scan on the telecine transfer device without risking harm to the original negative.
Telecine devices scan each negative or positive film frame transforming the transmittance at each pixel of an image into an electrical signal (e.g., a voltage). The signal processing then inverts the electrical signal in the case of a transfer made from a negative film in order to render a positive image, making a positive photographic print and then transferring the print film information into a video signal. The signal is carefully amplified and modulated, and fed into a cathode ray tube monitor to display the image. The signal can also be recorded onto magnetic tape for storage in, for example, a recording stage.
The output of the telecine transfer process finds a number of imagery applications. For example, video dailies are replacing the film dailies or rushes and non-linear editing techniques are replacing conventional film editing. The output of the telecine scanning process may be applied to a film recording stage, which produces a negative film that can be optically printed out as a release print. Ordinarily, a colorist operates a telecine transfer device by adjusting the telecine settings, which include gain, gamma, lift, illumination, matching whites, and matching blacks, to allow for the scene to be captured on the video tape correctly. The amount of latitude in setting up the telecine controls can cause clipping of data as well as viewing of a flat image on the monitor. The colorist may then have to color grade each scene, spending more telecine time and consequently adding more expense to the production job. That is, there are several drawbacks of this current practise. First of all, the dp has little control over the look of the dailies. Secondly, there is no “language” of printer lites or describable quantities to inform the dp how the negative was exposed and how much latitude exists for future correction.
More specifically, a major drawback of all these video applications is that the video signal resulting from the telecine transfer process has to be custom processed for each application. That is, an acceptable scene reproduction is obtained from dailies created on a trial-and-error basis, which is generally time-consuming. In case the cinematographer is not pleased with the scene look on the daily, the whole process is then repeated, starting with new adjustments and ending with another telecine transfer, until the desired look is obtained. Besides being time consuming, this is a relatively expensive process. Also, the telecine transfer method typically does not offer a quantitative assessment of the film system exposure information and does not provide, as in prior art systems, repeatable and reproducible values from which a cinematographer/director of photography could order the color correction of the film in a manner understood by a color correction specialist or “timer”.